How to apply gradient to both fill and stroke on entire image

Relexious,

Always save (a copy of) the original artwork before you destroy it (by outlining and whatever).

Apart from that there is a way to keep the artwork shapes/strokes unchanged and thereby edible, also after the gradien appearance is obtained:

1) Group (or make a compound path of) the artwork if not already, and change the colour (of both stroke and fill) to black if not already;

2) Create a path larger than the artwork and apply the desired gradient to it (you may set it to less than 100% transparency so you can see (it on top of) the artwork from 1);

3) When you are satisfied, select 2) and Ctrl/Cmd+X+B to move it behind the artwork from 1);

4) Select everything and in the Transparency palette flyout click Make Opacity Mask with both Clip and Invert Mask ticked.

That should give you the appearance of the gradient as desired across both stroke and fill of the entire artwork.

If desired, you can release the mask, make changes, and reapply.

Hope it works well for you!

Thanks guys, helped alot.

It's possible that after following the advice from michelew83603738 above, you may have to select all object and drag across them with the Gradient tool (G). Click with the Gradient tool where you'd like the Gradient to start and drag at an angle you'd like the Gradient to follow, then release your mouse where you'd like the Gradient to end.